Bar-chair used in concrete construction.



J. R. ODONNELL.

BAR CHAIR USED IN CONCRETE CONSTRUCTEON.

APPLICATION FILED Aue.1B,'191s.

Patented Apr. 11, 1916.

2 SHEETS--SHEET l/Vl /E/VTOR flu W Q BY M.

ATTORNEY &: 0i; TOLLW WITNESSES HE COLUMBIA PLANOG 1. R.'0DONNELL. BAR CHAIR USED IN CONCRETE CONSTRUCTION.

APPLICATION FILED AUG. 18, 1915.

Patented Apr. 11, 1916.

2 SHEETSSHEET 2.

l/VVE/VTOR ATTORNEY WITNESSES /Q. 4 1 T- CL. WW

THE COLUMBIA PLANUGRAPH co, WASHINGTON, D. c.

JOHN nfononnnnn, or N W YORK, N. Y.

BAR-CHAIR USED IN CONCRETE CONSTRUCTION.

Specification of Letters Patent.

Patented in. ii, ieie.

Application filed August 18, 1915. Serial No. 46,050.

This invention relates to means known as bar chairs for supporting and locating in certain predetermined positions, reinforclng,

bars for concrete construction work.

Inall reinforced concrete construction work, the beams and girders are reinforced by bars running lengthwise thereof. These bars are placed in the form before the concrete is poured therein. Usually they are located in the lower part of the beam or girder; and it is frequently essential for the purpose of fireproofing that a certain specified amount of concrete cover the bars. It is likewise essential that the bars be so supported as to limit their possible movement from the bottom of the beam. The bar chairs now and heretofore in use for supporting these reinforcing bars frequently tip and the result is that a workman loses time in relocating the chair; or if the tipping remains undiscovered, the reinforcing bar will not be maintained in correct position; and the bar will not be fireproofed.

The object of my invention is to provide a bar chair that is simple, cheap to manu facture, easy to place in position, non-tippable, and which will accurately position the reinforcing bar in the beam or girder.

For fuller explanation and description, reference is hereby made to the accompanying drawings, of which Figure 1 is a vertical section through a section of reinforced concrete construction, showing part of the floor and a beam or girder to which my invention is applied. Fig. 2 is a sectional view taken on the line 22 of Fig. 1. Fig. 3 is a vertical cross section of a beam or girder illustrating a method of using my invention. Fig. 4 is a sectional view illustrating a slightly different embodiment of my invention. Fig. 5 is a sectional view showing the'floor, beams, girders and columns and the method of applying my invention. Fig. 6 is a perspective view of a form of my improved chair. Fig. 7 is a sectional plan view showing how the chair is located in the form or mold.

Fig. 8 is a perspective view of a chair-flange provided with means for keeping the chair from-rolling. v a

Referringagain-to the drawings, 10 designates the floor supported, by beams 11, girders 12, and columns 13, (Fig. 5). In allconcrete construction work, the forms are erectedflrst; and in the drawings, 14. represents thefloor form, 15 the side forms for the beam or girder, and 16 the bottom form.

After the forms have been erected the reinforcing bars17 are placed in position' These bars are adapted to run lengthwise of the beam, some of them running parallel to the bottom of beam as 18 (Figs. 1 and 5) and others 19 are bent so as to bring their ends up near the level of the floor.

To support the bars, I provide an improved chair 20. As shown in Fig. 5, two

of these chairs 2O are'placed in a span between girders or beams, thus affording the bars a support near each end. These chairs 20 consist of aseries of hub portions 21, provided with flanges 22, said hubs 21, being mounted on or made integral with a shaft 23.

16 of the beam or girder and the hub por tion 21 supports the bars 17. While the drawings show only two bars supported on a line it is understood that a plurality of hubs and flanges may be provided to sup port any number of bars on the same level.

In Figs. 2 and 8 a shoulder 24:, having adouble row of bars may be readily supported by resting 'a second chair on the lower set of bars. I V

Fig. 4: shows a slightlydifferent form of my improved chair in which the bars 17, rest directly on a shaft 25 (Fig 6) and flanges 26 support the chair from the bottom, said flanges 26 resting on the bottom board of the form. Smaller flanges 27 are provided to confine the bar to its proper position.

Fig. 7 shows how the chairs should be placed in the form. Itwill be noted that It is obvious from the drawings that the flange part 22 rests on the bottom form the longitudinal axis of the shaft 25 is slightly skewed oil so as not to be at regular angles to the sides 15 of the form. (Of course, if the hexagonal formof flange-is employed, it will not be necessary to place the chair in this skewed position.) Theresult is that if anything happens to make the chair r011 slightly the limit of movement would be to the dotted position 28, as one of the ends of theshaft 25 would'bind against the side form 15.

Having now described my invention,'what I claim as newand desire tosecure by Letters Patent is:

1. In a bar-chair for concrete construction, a shaft carrying circular flanges spaced apart to permit the disposition of a bar therebetween, one of said flanges being proone of said flanges being provided with meansfor limiting the rolling of said chair.

8. A bar-chair for concrete construction, comprising a shaft hubs carried thereby, and circular flanges at thefiends of said hubs,

- one of said flanges beingprovided with a "shoulder limiting the rolling of said chair.

Signed at'NeW York city, this 11th day Of August, 1915.

'JOHN R. ODONNELL. WVitnesses GRACE H. 'ENPEY,

CLARENCE G. GALsToN.

Copies of this patent may be obtained forfive cents-each, by'addressing'the Commissionerof Patents,

Wa'shington,"D. G. v 

